Correlation between the pathogenesis of bronchial asthma and serum expressions of IL-4, IL-12, IL-37 and 25-(OH)D.

Wheezing is a common symptom of respiratory diseases. A survey found that about 1/3 of all children had at least one episode of wheezing before reaching the age of 3, and about 1/2 of them had at least one episode of wheezing by the age of 6.